DE8811363U1 - Axial compensator with blocking device - Google Patents

Description

Axial compensator with blocking device

The invention relates to an axial compensator with two pipe sockets connected via a length-adjustable expansion part, wherein the expansion part is overlapped by at least one dumbbell tube firmly connected to a first pipe socket, and with a detachable blocking device between the jacket tube and the second pipe socket.

Such an axial compensator is used with its connection or pipe socket between the ends of pipes in a piping system. The pipes are subject to thermally induced length changes, which are absorbed by axial compensators, among other things. The jacket pipes can serve as a guide device for mutually guiding the pipe sockets and for transmitting additional transverse forces and moments.

In many applications it is planned or required to subject the compensator or the pipes with the compensator installed to a pressure test. This pressure test is carried out under considerable internal pressure of-

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which would result in the expansion part being stretched to its maximum length and thus overstretched, so that it would have no or only very little expansion reserves in the sense of further bellows expansion if its expansion were not limited during the pressure test.

For example, blocking devices have already been proposed which protect the compensator against over-stretching during the pressure test and are only released after this, if necessary after the first expansion of the pipe system and thus compression of the expansion part below a certain length. Thus, according to DE-OS 32 OO 842, a radially elastic spring ring is arranged between a pipe socket and an adjacent movable end of the dumbbell pipe, which is held in an axial displacement between the pipe socket and the jacket pipe in the sense of a bellows elongation preventing blocking position and in another radial position assumes a release position enabling axial displacement.

In a similar axial compensator, the casing pipe is replaced by individual brackets arranged on the circumference, spanning the expansion element, sitting on the pipe socket and able to move axially. The brackets are held in place by a spring ring and the axial movement is limited by rings sitting on the pipe socket. A releasable blocking device with a spring-loaded hinge is provided (EF-OS 132 619).

In contrast, the invention is based on the object of creating an axial compensator of the generic type which is of simpler design and has a high degree of functional reliability. Likewise, compared to DE-OS 32 00 842, the advantageous reduction in surface pressure is to be achieved by enlarging the contact surfaces.

According to the invention, the above-mentioned object is achieved in a generic axial compensator in that the locking device

device has a locking device arranged between the jacket pipe and the second pipe socket, which can be pivoted into a release position under the action of a spring ring. The spring ring can be moved by a driver, whereby the locking device is pivoted into a release position . The spring ring locks the locking device in its position and prevents the locking device from remaining in the compensator indefinitely. Preferably, two or more locking devices are arranged symmetrically around the circumference of the second pipe socket.

In a preferred embodiment, the spring ring is axially movable.

Further preferred embodiments provide that the locking device has travel limiting formations for the spring ring, whereby in particular the locking device has a nose which engages behind the spring ring in the blocking position and/or that the locking device has a groove which receives the spring ring in its release position.

Further developments also provide that the driver in a blocking position engages behind the spring ring on the side facing away from the expansion part, whereby the spring ring can be moved along the locking mechanism in the axial direction when the bellows is first compressed by the driver. The geometric design of the locking mechanism in conjunction with the recesses in the casing tube makes the use of a swivel bolt with hinge wings, as in EP-OS 132 619, obsolete.

Further advantages and features of the invention emerge from the claims and from the following description, in which an embodiment of the device according to the invention is explained in detail with reference to the drawing.

Figure 1 An axial compensator according to the invention in longitudinal section/where the longitudinal axis A indicates the axis of symmetry ;

Figure 2 is an enlarged partial view of the functional parts designed according to the invention and

Figure 3 is a cross-sectional view of the functional parts designed according to the invention.

The axial compensator 1 according to the invention has an expansion element or part 2 in the form of a bellows, which is provided at its ends with pipe sockets 3, 4 for use in a pipeline. A jacket pipe 6 is firmly attached to the pipe socket 3, which in the preferred embodiment shown extends over an inner jacket pipe 6a with the expansion element 2 located underneath and overlaps this.

This can be done, for example, by first firmly welding a spacer ring to the pipe 3, to which the cylindrical jacket pipe 6 is in turn welded. Instead, the jacket pipe 6 could also be drawn in in this area up to the circumference of the connection piece 3, as can be seen from the attachment. The second pipe piece 4 has a retaining ring 8 firmly connected to it, for example welded, near its attachment point with the expansion element 2. A driver 9 is arranged at a distance from this retaining ring 8, over which its spring ring 11 is guided, which is compressed in the provided locking or blocking position by a locking lock 12 arranged between it and the jacket pipe 6. The locking lock 12 rests against the bellows ring 8 with its end face 13 facing the bellows 2. It has two lugs 14, 16 arranged at a distance from one another, which protrude through rectangular openings 17, 18 in the dumbbell tube. The retaining ring 11 is prevented from axially moving away from the expansion element 2 in its blocking position shown in the figure by a lug 19 of the driver 9 engaging behind it.

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and also partially engaged by a nose 21 of the locking mechanism 12.

The locking device 12 has a transverse groove 22 near its front side 13 below the nose 14. The axial compensator is held with the locking device 12 in its illustrated position by a shearable shear pin 24.

The driver 19 can be designed to be ring-symmetrical, just like the retaining ring 8, but it can also be designed as a block locally under the closure lock 12. The closure lock 12 is definitely not designed to be ring-symmetrical. However, it is advantageous to arrange at least two or more closure locks as symmetrically as possible around the circumference of the connection piece 4.

The expansion element and connection piece are assembled in the usual way. The assembly of the blocking and unlocking device designed according to the invention, which is essentially formed by casing 6, retaining ring 8, locking device 12, spring ring 11 and driver 9, is carried out in the following way:

First, the retaining ring 8 is pushed over the pipe socket 4 to a position determined by the individually desired pre-tension length of the compensator and secured to it, usually welded. The locking device 12 is then inserted, if necessary with slight tilting, into the punched-out, rectangular recesses 17, 18 in the protective casing pipe 6 and the spring ring 11 is pushed behind the nose 21 of the locking device 12, whereby it is held in this position by its spring effect. The protective casing pipe is then guided over the expansion element 2 and the locking device 12 is thus pushed behind the retaining ring 8 (seen from the expansion element 2).

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The protective jacket pipe 6 is then indirectly firmly connected/namely welded to the first pipe socket 3 at its end 6a opposite the recesses 17, 18 in the manner explained.

The driver 9 is then fixed to the second connection piece 4 and also welded in such a way that its nose 9 engages behind the spring ring 11. The prefabricated end piece 25 of the outer casing pipe is then connected to it by welding. By placing the shear pin 24 in the torsion lock 26, the axial compensator is locked in position for delivery.

The compensator thus completed can now be tested. To do this, a test overpressure is introduced into it. This causes the expansion cement 2 to expand. A force Fp from the expansion element 2 thus acts on the end of the second pipe socket 4 connected to the expansion element 2. This force is transferred from the pipe socket 4 via the retaining ring 8 to the locking device 12 and from there via the nose 14 to the casing pipe 6 and via this to the first connection socket 3. This limits the expansion of the expansion element 2 under test pressure.

This test pressure can be applied after the axial compensator has been installed in the pipeline. The shear pin is sheared off by the expansion movement when the pipe system expands for the first time. When the pipe system expands axially in this way, the capacitor is compressed and a force Fd acts on it, as indicated in the drawing, i.e. the two pipe sockets 3, 4 are pressed against each other. As a result, the driver 9 reaches behind the spring ring 11 with its nose 19 and pushes it away from the nose 21 of the locking device 12 towards the expansion element 2. The spring ring 11 presses the locking device outwards from its blocking position shown in the figure until it snaps into the groove 22 and thus locks the locking device 12 in its release position with the end 13 pivoted outwards compared to the position shown.

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in which the front side 13 can no longer be caught in contact with the retaining ring 8. This ensures the free mobility of the retaining ring 8 and the driver 9 and accordingly of the pipe socket 4 in the pipe system and relative to the other pipe socket 3, so that the expansion element 2 and thus the entire compensator 1 can fully develop its compensating effect.

Claims (1)

Axial compensator with two pipe sockets connected by a length-variable expansion part, the expansion part being overlapped by at least one jacket pipe firmly connected to a first pipe socket, and with a releasable blocking device between the jacket pipe and the second pipe socket, characterized in that the blocking device has a locking lock (12) arranged between the jacket pipe (6) and the second pipe socket (4) and which can be pivoted into a release position under the action of a spring ring (11). Compensator according to claim 1, characterized in that the spring ring (11) is axially movable. Compensator according to claim 1 or 2, characterized in that the locking device (12) has travel limiting formations (21, 22) for the spring ring (11). I I I I * I * «II 4. Compensator according to claim 3, characterized in that the locking device (12) has a nose (21) which engages behind the spring ring (11) in the blocking position. 5. Compensator according to claim 3 or 4, characterized in that the locking device (12) has a groove (22) which receives the spring ring (11) in its release position. 6. Compensator according to one of the preceding claims, characterized in that the locking device (12) forms a positive connection between the retaining ring (8) and the protective casing tube (6) as a blocking position. 7. Compensator according to one of the preceding claims, characterized in that the driver (9) in a blocking position engages behind the spring ring (11) on the side facing away from the expansion part (2). 8. Compensator according to one of the preceding claims, characterized in that the spring ring (11) is displaced when the bellows (2) is first compressed by the driver (9) can be moved along the locking mechanism (12) in the axial direction. 9. Compensator according to one of the preceding claims, characterized in that the locking device (12) can be rotated out of the blocking position via the spring ring (11) when the bellows (2) is compressed for the first time by the driver (9). 10. Compensator according to one of the preceding claims, characterized in that the locking device (12) is held in its position by the spring ring (11) after the spring ring (11) has snapped into the recess (22). • >ll I t I «f · 11. Compensator according to one of the preceding claims, characterized in that the expansion part (2) is overlapped by two jacket pipes (6, 6a) which are firmly connected to the other pipe sockets (3 or 4).